Method and apparatus for tracking documents in a workflow

ABSTRACT

A workflow system and method include tracking the physical movement of documents. The information of the physical movement is incorporated with the flow graph of a workflow. A display of the workflow can then be enhanced by the information relating to the physical movement of the document.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application incorporates by reference the entire contents of thefollowing applications for all purposes:

-   -   (1) U.S. patent application Ser. No. 10/235,035 filed        concurrently with this application;    -   (2) U.S. patent application Ser. No. 10/235,042 filed        concurrently with this application;    -   (3) U.S. patent application Ser. No. 10/235,032 filed        concurrently with this application;    -   (4) U.S. patent application Ser. No. 10/235,028 filed        concurrently with this application; and    -   (5) U.S. patent application Ser. No. 10/235,030 filed        concurrently with this application.    -   The present application incorporates by reference the entire        disclosure of the following patent for all purposes:    -   (1) U.S. Pat. No. 5,978,477, issued Nov. 2, 1999 entitled        “AUTOMATIC AND TRANSPARENT DOCUMENT ARCHIVING.”

BACKGROUND OF THE INVENTION

The present invention relates generally to workflow systems and moreparticularly to tracking documents in a workflow system.

During the course of running a business, there are many steps and peopleinvolved in each endeavor. Accompanying this activity might be the flowof large numbers of documentation. For example, documents generated by aperson or by people in a workgroup often require distribution to otherpeople in the company or among different groups of people. Workflowsystems provide a way for managing the flow of numerous documents duringthe course of a project.

Any substantial project is likely to produce volumes of paperwork.Effective management of a large-scale project requires up to dateinformation. In the case of documents, it is important to know who haswhat document, how far along a document is in the review process, and soon. This can facilitate identifying critical paths and bottlenecks. Itis therefore desirable to be able to enhance a workflow system toimprove its utility.

SUMMARY OF THE INVENTION

A workflow system and method comprise one or more sensors disposed aboutan area of the workflow. The sensors detect proximity of a document asit is moved about in the area of the workflow. The information collectedis associated with information relating to the document. The workflowsystem integrates this information with a display of the workflow graph,reflecting the movement of documents in the workflow. The workflow graphcan be presented in graphical form, showing a graphical representationof the workflow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram of a sensor arrangement formonitoring documents in accordance with an embodiment of the presentinvention;

FIG. 2 illustrates an example of workflow;

FIGS. 2A and 2B show enhancements to a conventional workflow accordingto the present invention;

FIGS. 3A and 3B show a radio identification system as used in animplementation of an embodiment of the present invention;

FIG. 4 illustrates high level processing according to the invention;

FIG. 5 show various sensor configurations for detecting actions that canbe performed on a document;

FIG. 6 illustrates an example of a workflow appliance in accordance withthe present invention;

FIG. 7 illustrates an example of a partial workflow diagram of a formsprocessing system; and

FIG. 8 illustrates a conventional XML representation of the workflowfragment shown in FIG. 7.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

FIG. 1 is a highly generalized block diagram of a document workflowsystem in accordance with an embodiment of the present invention. Aworkflow processor 102 represents the component that provides thefunctionality commonly found in typical workflow systems. Typically,this includes a computer component, such as a personal computer, runningappropriate software. It can be appreciated that the workflow processorcan be any appropriate computing configuration or platform. Somefunctions provided by a workflow system include identifying documents tobe routed in the workflow. The workflow includes a workflow graph whichidentifies the paths along which the participating documents are to berouted.

Referring to FIG. 2 for a moment, a portion of a typical workflow isillustrated. This representation is an exemplar of a graphicalrepresentation of a workflow, used to illustrate aspects of embodimentsof the present invention. It can be appreciated that actual workflowsystems will include additional tools for the user.

A workflow comprises a plurality of stages (nodes of the graph) 212a-212 c and 214 a-214 c, for example, at which an action is performed onthe document(s). Each stage represents a location in the operation wherethe document can be routed; e.g. someone's office, or some otherappropriate location for a particular given operation. The action may bea simple acknowledgment of having received the document, or the actionmay be something more interactive such as a review and/or editing orother annotation made to the document. The action may be a copyoperation, a fax operation, or the like. There can be different kinds ofstages. For example, stages 212 a-212 c are examples of simple store andforward stages where a document is received, an action might beperformed on the document, and the document is then passed on. Stages214 a-214 c, for example, are branching stages where the document flowcan proceed along alternate paths. The workflow is further defined byedges 202 a-202 d, for example, which connect the stages together tocomplete the flow graph.

In the particular example shown in FIG. 2, a graphical representation ofa workflow is illustrated. It can be appreciated, however, that otherrepresentational forms are possible. For example, it may be moreappropriate under certain situations to represent a workflow in atextual format. A machine interface may use a representational form moresuitable for communication among computing equipment.

Returning to FIG. 1, the workflow processor 102 may be provided withappropriate user interfaces 106 a, 106 b. As noted above, the userinterface can be a graphical user interface (GUI) presented on asuitable display device and having appropriate input devices (e.g.,keyboard, voice input, mouse, and other commonly used input devices) tofacilitate creating and editing workflows. While a GUI is an appropriateinterface, a textual interface can also be used. Each user interface isin communication with the workflow processor via an appropriatecommunication channel 116, such as a network-type of connection, adirect connection to the processor, a modem connection, and so on.

The workflow system shown in FIG. 1 further includes a sensor processingcomponent 104. This component can comprise a single computer device, orother appropriate configuration. Sensors 108 a-108 d are disposed aboutthe plurality of locations which can be included in a workflow. In oneparticular implementation of an embodiment of the invention, thelocation of each sensor is known to the sensor processing component. Inanother particular implementation, each sensor can provide informationabout its location to the sensor processing component. Each sensor cancommunicate information to the sensor processing component over achannel 114.

It can be appreciated that in a large enterprise, the sensors might verywell be distributed over a large geographic area. In such a case, thesensor processing component 104 might comprise a network of localcomputers where each local computer handles sensors local to thatcomputer. For example, a set of sensors in an office in Paris might belinked to a local computer in that office, while a second local computermight be used to link together the sensors in an office in Tokyo. Insuch cases, it is understood that an element (e.g., sensor 108 c shownin FIG. 1) can be viewed as a logical, recursively defined,representation of a local sensor group, comprising a plurality of localsensors and a local computer communicating. The local computercommunicates sensor data from its local sensors to the sensor processor104.

In accordance with this embodiment of the invention, each sensor 108_(i) is sensitive to proximity of one or more documents being routed ina workflow. In a particular implementation of this embodiment of theinvention, a radio frequency identification (RFID) system constitutesthe sensor subsystem. RFID is a versatile wireless solution foridentification. It has a wide range of applications, from tracking booksin a library to monitoring the movement of cattle on a ranch.

Referring for a moment to FIGS. 3A and 3B, a basic RFID system comprisesthree components: an antenna component (coil) 313, a transceivercomponent 312, and a transponder (commonly called an RFID tag) 316. Theantenna component 313 emits radio signals to activate the tag 316.Antennas are available in a variety of shapes and sizes.

Often, the antenna component 313 is packaged with a transceivercomponent 312 which typically includes a decoder module. Thiscombination is referred to variously as a reader, an interrogator, andso on. In operation, the reader can emit radio waves 322 (interrogationsignal) in ranges of anywhere from one inch to several feet or more,depending upon its power output and the radio frequency used. Thetransceiver component produces the interrogation signal which is thenpropagated by the antenna component.

When an RFID tag passes through the electromagnetic zone of theinterrogation signal, it responds to that signal and produces a responsesignal 316 which is picked up by the antenna component 313 and fed tothe transceiver component 312. The decoder module in the transceiverdecodes the response signal to extract the data encoded in the tag andthe data is passed to a host computer for subsequent processing.

RFID tags come in a wide variety of shapes and sizes. Some tags can onlybe read, while other tags can be read and written. For example, aproduct called the MU-chip by Hitachi, Ltd., is a 0.4 mm² chip that isthin enough (about 60 μm) to be embedded in paper, and contains aread-only memory (ROM) of 128 bits.

RFID tags are categorized as either active or passive. Active RFID tagsare powered by an internal battery and are typically read/write, i.e.,tag data can be rewritten and/or modified. The battery-supplied power ofan active tag generally gives it a longer read range. The trade off ofcourse is greater size, greater cost, and a limited operational life dueto the limited life of the battery. Nonetheless, it can be appreciatedthat active tags can be useful in the present invention underappropriate operational requirements.

Passive RFID tags operate without a separate external power source andobtain operating power generated from the interrogation signaltransmitted from the reader. Passive tags are consequently much lighterthan active tags, less expensive, and offer a virtually unlimitedoperational lifetime. The trade off is that they have shorter readranges than active tags and require a higher-powered reader. Read-onlytags are typically passive and are programmed with a unique set of data(usually 32 to 128 bits) that cannot be modified. For example, theHitachi MU-chip comes preprogrammed with a 128 bit data word.

In accordance with the present invention, physical documents have one ormore RFID tags physically associated with them. Such documents can bereferred to as “tagged documents.” A plethora of attachment processesare possible. An RFID tag can be attached by the use of adhesives. Aclip which gathers together a multi-page document can be provided withan RFID tag. For example, a paper clip may incorporate a tag, or astaple can be incorporated with a tag.

The attachment can be manual, or by automation. For example, a copyingmachine can be outfitted with RFID tagged staples or a dispenser ofadhesive tags, so that stapled copies can be tagged by way of thestaple, or single-page copies can be tagged with an adhesive tag. RFIDtags (e.g., Hitachi MU-chip) can be embedded in the paper medium itself(“tagged paper”).

In accordance with this particular implementation of an embodiment ofthe invention, each RFID tag is associated with a unique identification,referred to herein as a “tag identifier.” Furthermore, when a tag isphysically associated with a physical document, there is an associationbetween the tag identifier and “document information” relating to thephysical document. The document information might comprise an electroniccopy of the physical document, an image of the document, a referencewhich identifies the physical or an electronic form of document, areference identifying where an electronic copy of the physical documentcan be found, references to other documents, and so on. The documentinformation might include information indicative of permissions, forexample, whether a document can be copied or not. The documentinformation might include ownership information, document modificationhistory information. In general, one can appreciate that any kind ofinformation may constitute “document information.”

The document information can be collected at the time of creation of thedocument; e.g., when the document is printed, copied, faxed, orotherwise processed. The document information can be an accumulation ofinformation collected during the lifetime of the document such as whenmodifications are made, or when copies are made, for example. A databasesystem (not shown) can be provided to store such information, or othersuitable information management system. The database or informationmanagement system can be used to provide the mapping between tagidentifier and document information.

Returning to FIG. 1, it can be appreciated from FIGS. 3A and 3B that theplurality of sensors 108 a-108 d can comprise the transceiver andantenna component of an RFID system. Each sensor 108 _(i) includes atransceiver circuit and an antenna for transmitting an interrogationsignal and for receiving a response signal from a document 132 a. Eachsensor further includes a communication component for communicatinginformation received from the tag 134 a embedded in a sensed document(i.e., the tag identifier) to the sensor processing component 104. Thesensor processor then associates the tag identifier with the particularsensor that transmitted the information. In an implementation of anembodiment of the invention, the location of each sensor is known apriori. Consequently, the sensor processor can make the furtherassociation of tag identifier with location of the tag and itsassociated physical document. Finally, the database system can provideto the sensor processor a mapping of the tag identifier with an identityof the sensed document. Thus, it can be seen that the location of adocument is known, insofar as the sensors can detect the document.

The workflow processing component 102 is in data communication with thesensor processing component 104 via communication channel 112.Communication between the workflow processor and the sensor processorcan be provided by any of a number of known communication techniques. Inone embodiment of the invention, the two processing components could besubsystems in the same computer system. On the other hand, in a largeenterprise where a distributed architecture may be more appropriate, thesensor processing component may comprise a plurality of local computersystems, each receiving tag information from its associated RFID tags.

The sensor processing component 104 transmits to the workflow processor102 information indicative of the sensed (detected) document(s) andinformation representative of the location where the document(s) weresensed. Alternatively, the sensor processing component might transmit tothe workflow processor the tag identifier along with informationindicative of the sensor 108 _(i) that received the information. Theworkflow processor can then make the necessary mappings to obtain adocument identifier and its physical location. In a distributedenvironment comprising plural sensor processing computers, some of thesensor processors may provide the mapped information to the workflowprocessor, while other sensor processors might transmit the “raw” datato the workflow processor.

Assuming the workflow processor 102 is in possession of informationrelating to a document and information indicative of its location, theinformation can be used to enhance the workflow graph. Referring to FIG.2A, the workflow segment illustrated in FIG. 2 is shown as it mightappear in a GUI. The figure illustrates a tracking feature of documentflow wherein the physical location of a document can be tracked withoutinformation provided by a user, sometimes referred to as “unconscious”tracking, automated tracking, and so on. Upon receiving an appropriatedisplay command from the user, the workflow graph presented to the user(on a display, for example, as shown in FIG. 2) can be enhanced withinformation from the sensors 108 _(i) received from the sensorprocessing component 104.

As an example, in FIG. 2A the current location 232 a of a document isindicated by highlighting (or some otherwise visually indicating) thenode (stage, 212 b) in the workflow which corresponds to that currentlocation. It can be appreciated, of course, that other indicatingtechniques can be used. Additional information 222 a can be presented aswell. For example, information indicating an action taken on thedocument might be displayed, if available. The additional informationcan be another document(s) that has become associated with the document;for example, a reviewer of the document might attach, or otherwiseassociate, a related document to the document in the workflow.

FIG. 2A further illustrates that a document can be routedelectronically. Thus, for example, stage 214 c is the current location232 b of a second document. Here, the document is in electronic form.This can be indicated by a suitable graphic such as the “lighting bolts”234 intended to illustrate that the second document exists in electronicform.

FIG. 2B illustrates another feature of the workflow system of thepresent invention. The tracking information collected by the sensorprocessing component 104 can be used to compile a tracking history of adocument in the workflow. The figure shows an example of such a display.A tracking history 242 comprises highlighted portions of the workflowindicating the stages and edges which constitute movement of thedocument in the workflow. Thus, for example, the edges 246 a-246 c andothers are indicated by highlighting, or some equivalent visualindication. The stages where the document was sensed are also shownhighlighted. Collectively, the highlighted portions pictorially show theflow of the document. It might be useful to have additional information244 a-244 e associated with each stage in the tracking history. Forexample, a time stamp indicating the time of detection at each stage canbe stored and displayed. Other additional information 222 a can beassociated with each stage as discussed above; e.g., action taken on adocument, related documents can be associated with the document beingtracked, and so on.

FIG. 4 is a high-level flow chart illustrating processing steps of aworkflow system according to the foregoing aspects of the presentinvention. At a step 402, a sensor 108 _(i) detects the proximity of adocument 132 a. This includes receiving a response signal from the tag134 a that is physically associated with the document in response to aninterrogation signal. The response signal includes informationindicative of a tag identifier associated with the tag. At a step 404,the sensed tag information is associated with information indicative ofthe location of the sensor which detected the response signal. Asdiscussed above, locations of sensors can be known a priori by thesensor processing component 104. Alternatively, a sensor can beappropriately configured to communicate some information along with thetag identifier that indicates an identity of the sensor itself. Amapping of the sensor identity can be made to determine its location. Inyet another alternative, an indication of the location of the sensor canbe communicated to the sensor processing component. A time stamp can beassociated with the tag identifier to indicate when the document wasdetected and the location of the detection.

At a step 406, the tag identifier is associated with the document. Thiscan be accomplished using information contained in a database 122, forexample containing a mapping between tag identifiers and documentidentifiers.

Certain actions can be taken on the document at steps 408 and 410. Forexample, the recipient may simply acknowledge receipt of the document.The user may annotate or otherwise modify the document; e.g., byassociating other documents with it, and so on. The user interface 106_(i) can provide the necessary access and functionality to effect suchactions. These actions can then be associated with the tag identifier bythe workflow processing component 102.

The user can enter a display command at a step 412 to display all or aportion of the workflow. The user might submit a command to display thecurrent location of a particular document or documents. At a step 414,the association among the information made in the foregoing steps can beused to identify the location(s) of the document(s). The workflow canthen be displayed where those stage(s) corresponding to the identifiedlocation(s) are highlighted in an appropriate manner to show theircurrent locations. If tracking history is desired, then in a step 416the workflow graph can be displayed in a manner to highlight the flow ofthe document in the workflow graph.

FIG. 5 shows some additional sensors which can be incorporated invarious document processing devices. A copying machine 502 can beequipped with a sensor 508 a. Thus, if a copy of a tagged document 530 ais made, the sensor can detect the presence of the tagged document andindicate to the sensor processing component 104, the action of a copyhaving been made. This action is then associated with the tagidentifier.

Similarly, a printer 504 having a sensor 508 b can detect printing ofmaterial. Stock paper, having physically associated with it one or moretags, can be detected by the sensor when processing a print job sent bya PC 510. A communication link 514 from the printer and the PC canprovide to the sensor processing component 104 information indicatingthe tag identifier and the document being printed. This establishes theexistence of the printed document, and subsequent tracking of thedocument in the workflow. In addition, the action of the printing of thedocument can be associated with the document, and subsequently displayedto a user in the manner discussed above (see, e.g., FIGS. 2A and 2B).

The element 504 can also represent a scanner device having a sensor 508b. When a tagged document is scanned, the sensor can detect the tag ofthe scanned document and communicate the tag identifier to the sensorprocessing component 104. The scanned data is stored in the PC as adocument. A document identifier can be communicated to the sensorprocessing component to be associated with the tag identifier. In thisway, a tagged document in the workflow can be converted to electronicform. This action of scanning can be captured and associated with thedocument.

FIG. 5 shows a facsimile transmission (fax) device 506. This device isalso equipped with a sensor 508 c. When a tagged document in theworkflow is faxed to a recipient via the fax device, the sensor obtainsthe tag identifier and communicates that information to the sensorprocessing component 104. There, the tag identifier is associated withthe document identifier, as well as the action of being faxed. Inaddition, the fax device can communicate the fax number of the receivingmachine to the sensor processing component.

FIG. 6 shows an implementation of an embodiment according to anotheraspect of the invention, incorporating the use of re-writable RFIDchips. When the RFID chips embedded in documents are re-writable, an“autonomous” workflow functionality can be provided for users notconnected to an online workflow processor 102. This can be done bydescribing the workflow that contains the given document 602 and theposition of the document in that workflow in a standard way. Such adescription language would provide a means to specify the actions thathave been performed on that document and the actions that can beperformed on it in the future.

Users would scan a re-writable RFID chip 602 a contained in the document602 using a suitable device 612 (more abstractly referred to as aworkflow appliance). The workflow appliance can include a CPU (centralprocessing unit) or other similar data processing component 622, amemory component 624, a display 626, and a device 628 for reading andwriting the RFID chip 602 a and to provide user services such as loggingin and so on. The workflow description 614 can be downloaded from theRFID chip to the workflow appliance which displays the workflow diagram.The display can indicate where the document is in that diagram and whatactions the user could take on that document. After the user takes oneof those actions, it is recorded on the chip and the diagram is updatedand rewritten on the chip. That data can optionally be encrypted withthe next receiver's public key. When that user opens the document, hecan decrypt it with his private key.

If the workflow description language is in a standard format, users ofan autonomous workflow system can easily process documents produced bydifferent service providers. For example, Blue Cross might use an OracleWorkflow system for their medical claim forms and Cigna might use an IBMsystem. However, the workflow appliance in a Doctor's office does notneed to know that. The information added to the form, such as the name,address, and diagnosis code for the patient, can be recorded on the chipusing the standard format.

A further aspect of the various embodiments of the present inventioninclude information recorded on the re-writable RFID tag 602 a to directthe user to take certain actions. This provides a certain level ofautonomous behavior in the document, where the document can require therecipient of the document to take actions in a context-directed manner.Information can be written to the RFID tag 602 a along the way in theworkflow at its various stops by a backend workflow server. Theinformation in the RFID can be updated at each stop, or only at certainstops, depending on the situation. In an extreme case, the RFID cancontain the entire workflow in which case the document is in essence afully autonomous document, instructing it's recipients (via anappropriately configured workflow appliance) where the next stop is, orwhat the next action is.

For example, the fragment of a workflow diagram 700 depicted in FIG. 7shows an action 702 a being requested of a user Jan Brady. She has beenasked to enter the identification information for the patient, thediagnosis code, and to send the form to the employer's account manager.The routing information for the possible receivers (the accountmanagers) is provided so Jan knows where to send the paper form after ithas been filled out. This diagram fragment can be represented in atext-based format (e.g., XML) as shown in FIG. 8. Before the form isfilled out, the status 702 b is “awaiting completion.” After the formhas been filled out, the status is changed to “in transit” as it isbeing sent to the intended receiver. Since the hypothetical patientworks for the Ricoh company, the paper form was sent to Ronda Rice at223 Villa Boulevard, West Caldwell, N.J. since she's the benefitsmanager for that company. It can be appreciated that this aspect of theinvention allows for disparate workflow systems to co-operate, despitethe differences in workflow procedure and policy that are likely toexist among the different systems. The amount of information containedin the RFID tag, of course, will depend on the storage capacity of thedevice. Additional devices may be incorporated. It can be appreciatedthat system requirements, functional requirements, performancerequirements, and other such factors will determine specificimplementation details.

An external workflow system can be informed of this updated workflowdiagram either online, or asynchronously (e.g., via an email message),or not at all. Since the updated diagram is carried in the chip 602 a, anetwork connection is not required when the document's information isupdated. This can be a significant advantage since the physical locationwhere the update occurs does not need to be equipped with a networkconnection. In fact, a simple workflow status-updating appliance issufficient.

The workflow appliance reads the standard workflow description from thechip, determines the actions that are possible, displays those actionsto the user, provides a means for the user to enter the result of suchan action, and rewrites the memory of the chip to indicate the actionthat was performed. For example, the workflow appliance 612 shown inFIG. 6 can be suitably configured with appropriate software to processdocuments in a financial institution's workflow. The user is being askedto verify the validity of the signature on the form by comparing it toinformation in the account record. The result of this action, as well asthe time, date, and place where it was performed, are recorded on thechip. By reading and writing a standard workflow description language,the appliance can process documents that are represented in a workflowsystem provided by any vendor that supports such a standard interfacelanguage. Standard workflow interface descriptions that provideinteroperability between workflow systems are under development byindustry groups such as the Workflow Management Coalition (see, forexample, the web site at “http:\\www.wfmc.org”).

1. A method for monitoring documents in a workflow comprising: receivinga workflow graph representative of said workflow, said workflow graphcomprising information representative of one or more stages in saidworkflow; sensing a first document at a first sensed location;determining whether there is a first matching stage among said one ormore stages that corresponds to said first sensed location; associatingsaid first matching stage with document-related information relating tosaid first document; sensing said first document at a second sensedlocation; determining whether there is a second matching stage amongsaid one or more stages that corresponds to said second sensed location;and associating said second matching stage with said document-relatedinformation.
 2. The method of claim 1 further comprising: displaying arepresentation of said workflow graph; receiving a first user command;and in response to said first user command, providing in saidrepresentation of said workflow graph an indication of a currentlocation of said first document based on said first sensed location. 3.The method of claim 2 further including receiving a second user commandand in response thereto, indicating said first and second sensedlocations in said representation of said workflow graph.
 4. The methodof claim 1 further including receiving event information representativeof a user action performed on said first document while said document islocated at said first matching stage and associating saiddocument-related information with said event information.
 5. The methodof claim 4 further including associating with said document-relatedinformation time information indicative of the time when said useraction was performed.
 6. The method of claim 4 further includingdisplaying a representation of said stages of said workflow graph,including displaying a representation of said event information withsaid first matching stage.
 7. The method of claim 1 wherein said firstdocument is physically associated with an identification component thatcan be sensed when said first document is in proximity to said firstsensed location.
 8. The method of claim 1 wherein said sensing comprisestransmitting an interrogation signal suitable to produce a responsesignal in a radio frequency identification device (RFID) and detectingsaid response signal, said RFID being physically associated with saidfirst document.
 9. The method of claim 8 further including obtainingsaid document-related information based on said response signal.
 10. Themethod of claim 8 wherein said RFID is a re-writable device.
 11. Themethod of claim 10 wherein said document-related information includesinformation obtained from said RFID.
 12. The method of claim 8 whereinsaid document-related information includes one or more of an electroniccopy of said first document, information identifying said firstdocument, and information relating to a second document.
 13. A methodfor monitoring a document in a workflow, said workflow being representedby a workflow graph, the method comprising: at each of plural locations,sensing for presence of a document having physically associatedtherewith a radio identification device (RFID); accumulating a pluralityof first locations where said document was sensed; and presenting arepresentation of said workflow graph, said representation includinginformation indicative of one or more of said first locations therebymaking known one or more locations of said document in saidrepresentation of said workflow graph.
 14. The method of claim 13wherein said RFID is re-writable, the method further including recordinginformation representative of said plurality of first locations on saidRFID.
 15. The method of claim 13 wherein said RFID is re-writable, themethod further including recording on said RFID informationrepresentative of one or more actions taken on said document.
 16. Themethod of claim 13 wherein said sensing includes transmitting aninterrogation signal and detecting a response signal, said responsesignal being produced by said RFID in response to said interrogationsignal.
 17. The method of claim 13 wherein said sensing includesobtaining identification information representative of said document.18. The method of claim 13 wherein said workflow graph comprises aplurality of stages indicating an expected flow said document, themethod further including detecting a document flow deviation based onsaid expected flow and on said first locations.
 19. A document workflowsystem comprising: a first processing component; a second processingcomponent in communication with said first processing component, saidsecond processing component effective for receiving information whichconstitutes a workflow graph; and a plurality of sensors disposed abouta plurality of locations and in communication with said first processingcomponent, said sensors operable to sense a document and to transmitfirst information indicative of said document to said first processingcomponent, said first processing component operable to communicate tosaid second processing component second information indicative of alocation where said document was sensed, said second processingcomponent operable to identify said document in said workflow graphusing document-related information and said second information.
 20. Thesystem of claim 19 wherein each of said sensors is an interrogationdevice comprising a transceiver module for transmitting an interrogationsignal and for detecting a response signal, said interrogation signalsuitable for producing said response signal in a radio frequencyidentification (RFID) tag that is physically associated with saiddocument.
 21. The system of claim 19 wherein said second processingcomponent is operable to present a representation of said workflow graphwhich indicates said document relative to said workflow graph based onsaid second information.
 22. The system of claim 19 wherein said secondinformation includes time information indicative of when said documentwas sensed.
 23. The system of claim 19 wherein said first processingcomponent comprises a first computer system and said second processingcomponent comprises a second computer system in data communication withsaid first computer system.
 24. The system of claim 19 wherein saidfirst processing component and said second processing component arecomputer program components in a computer system.
 25. The system ofclaim 19 wherein said second processing component is operable tocommunicate a portion of said workflow graph to said first processingcomponent, said first processing element operable to communicate thirdinformation representative of said portion of said workflow graph tosaid sensors, wherein each of said sensors is an interrogation devicecomprising a transceiver module for transmitting an interrogation signalsuitable for storing said third information in a re-writable RFID (radiofrequency identification) tag that is physically associated with saiddocument.
 26. A method for monitoring documents in a workflowcomprising: receiving a workflow graph representative of said workflow,said workflow graph comprising information representative of one or morestages in said workflow; sensing a first document at a first sensedlocation; determining whether there is a first matching stage among saidone or more stages that corresponds to said first sensed location;associating said first matching stage with document-related informationrelating to said first document; sensing said first document at a secondsensed location; determining whether there is a second matching stageamong said one or more stages that corresponds to said second sensedlocation; and associating said second matching stage with saiddocument-related information, wherein said document includes are-writable RFID (radio frequency identification) tag and said step ofreceiving includes storing at least a portion of said workflow graph insaid RFID tag.
 27. The method of claim 26 further comprising: displayinga representation of said workflow graph; receiving a first user command;and in response to said first user command, providing in saidrepresentation of said workflow graph an indication of a currentlocation of said first document based on said first sensed location. 28.The method of claim 26 further including receiving event informationrepresentative of a user action performed on said first document whilesaid document is located at said first matching stage and associatingsaid document-related information with said event information.